﻿//--GoToTop start--
 var scrolltotop = {

        setting: { startline: 100, scrollto: 0, scrollduration: 1000, fadeduration: [500, 100] },
        controlHTML: '<div class="gototop_div"></div>', //HTML for control, which is auto wrapped in DIV w/ ID="topcontrol"
        controlattrs: { offsetx: 5, offsety: 5 }, //offset of control relative to right/ bottom of window corner
        anchorkeyword: '#top', //Enter href value of HTML anchors on the page that should also act as "Scroll Up" links

        state: { isvisible: false, shouldvisible: false },

        scrollup: function () {
            if (!this.cssfixedsupport) //if control is positioned using JavaScript
                this.$control.css({ opacity: 0 }) //hide control immediately after clicking it
            var dest = isNaN(this.setting.scrollto) ? this.setting.scrollto : parseInt(this.setting.scrollto)
            if (typeof dest == "string" && jQuery('#' + dest).length == 1) //check element set by string exists
                dest = jQuery('#' + dest).offset().top
            else
                dest = 0
            this.$body.animate({ scrollTop: dest }, this.setting.scrollduration);
        },

        keepfixed: function () {
            var $window = jQuery(window)
            var controlx = $window.scrollLeft() + $window.width() - this.$control.width() - this.controlattrs.offsetx
            var controly = $window.scrollTop() + $window.height() - this.$control.height() - this.controlattrs.offsety
            this.$control.css({ left: controlx + 'px', top: controly + 'px' })
        },

        togglecontrol: function () {
            var scrolltop = jQuery(window).scrollTop()
            if (!this.cssfixedsupport)
                this.keepfixed()
            this.state.shouldvisible = (scrolltop >= this.setting.startline) ? true : false
            if (this.state.shouldvisible && !this.state.isvisible) {
                this.$control.stop().animate({ opacity: 1 }, this.setting.fadeduration[0])
                this.state.isvisible = true
            }
            else if (this.state.shouldvisible == false && this.state.isvisible) {
                this.$control.stop().animate({ opacity: 0 }, this.setting.fadeduration[1])
                this.state.isvisible = false
            }
        },

        init: function () {
            jQuery(document).ready(function ($) {
                var mainobj = scrolltotop
                var iebrws = document.all
                mainobj.cssfixedsupport = !iebrws || iebrws && document.compatMode == "CSS1Compat" && window.XMLHttpRequest //not IE or IE7+ browsers in standards mode
                mainobj.$body = (window.opera) ? (document.compatMode == "CSS1Compat" ? $('html') : $('body')) : $('html,body')
                mainobj.$control = $('<div id="topcontrol">' + mainobj.controlHTML + '</div>')
				.css({ position: mainobj.cssfixedsupport ? 'fixed' : 'absolute', bottom: mainobj.controlattrs.offsety, left: mainobj.controlattrs.offsetx, opacity: 0, cursor: 'pointer' })
				.attr({ title: 'scroll to top' })
				.click(function () { mainobj.scrollup(); return false })
				.appendTo('body')
                if (document.all && !window.XMLHttpRequest && mainobj.$control.text() != '') //loose check for IE6 and below, plus whether control contains any text
                    mainobj.$control.css({ width: mainobj.$control.width() }) //IE6- seems to require an explicit width on a DIV containing text
                mainobj.togglecontrol()
                $('a[href="' + mainobj.anchorkeyword + '"]').click(function () {
                    mainobj.scrollup()
                    return false
                })
                $(window).bind('scroll resize', function (e) {
                    mainobj.togglecontrol()
                })
            })
        }
    }

    scrolltotop.init();
//--GoToTop end--